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基于钻头-岩石互作用的减振器应用效果分析 被引量:2
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作者 胡志强 祝效华 +3 位作者 王贺 梁建龙 杨含城 郑翔 《石油机械》 北大核心 2022年第10期8-13,43,共7页
在考虑钻柱、钻头和岩石系统动力耦合的基础上,以钻头破岩钻进的动态过程作为井底边界条件,研究减振器对其上端钻柱和下端钻头的减振效果。研究结果表明:应用减振器后,钻头钻压平均波动大幅度减轻,但纵向振动速度平均振幅变化不大;钻柱... 在考虑钻柱、钻头和岩石系统动力耦合的基础上,以钻头破岩钻进的动态过程作为井底边界条件,研究减振器对其上端钻柱和下端钻头的减振效果。研究结果表明:应用减振器后,钻头钻压平均波动大幅度减轻,但纵向振动速度平均振幅变化不大;钻柱纵向力和纵向速度平均振幅均明显降低;减振器应用效果随其刚度增大而降低,减振器刚度由3.5 kN/mm增大至6.5 kN/mm时,钻头、钻柱纵向力平均振幅分别增大了18%和46%;基于参数的研究分析,最优阻尼为60 N·s/mm;减振器距钻头越远,钻头振动越剧烈,减振器与钻头距离由1 m增大至28 m时,钻头振动强度增加了337%;减振器安装位置对钻柱振动强度影响不大,建议减振器尽可能近钻头安装。所得结论可为井下钻柱振动控制、减振器现场应用和参数优选提供参考。 展开更多
关键词 下部钻具 破岩钻进 减振器 非线性振动 纵向力
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The multifaceted role of post-translational modifications of LSD1 in cellular processes and disease pathogenesis 被引量:1
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作者 Yinrui Li Bo Wang +9 位作者 Yichao Zheng Huiqin Kang ang he Lijuan Zhao Ningjie Guo Hongmin Liu Adil Mardinoglu M.A.A.Mamun Ya Gao Xiaobing Chen 《Genes & Diseases》 2025年第3期168-179,共12页
Post-translational modifications(PTMs)of proteins play a crucial role in living organisms,altering the properties and functions of proteins.There are over 450 known PTMs involved in various life activities.LSD1(lysine... Post-translational modifications(PTMs)of proteins play a crucial role in living organisms,altering the properties and functions of proteins.There are over 450 known PTMs involved in various life activities.LSD1(lysine-specific demethylase 1)is the first identified histone demethylase that can remove monomethylation or dimethylation modifications from histone H3 lysine K4(H3K4)and histone H3 lysine K9(H3K9).This ability of LSD1 allows it to inhibit or activate transcription.LSD1 has been found to abnormally express at the protein level in various tumors, making it relevant to multiple diseases. As a PTM enzyme, LSD1 itself undergoes various PTMs, including phosphorylation, acetylation, ubiquitination, methylation, SUMOylation, and S-nitrosylation, influencing its activity and function. Dysregulation of thesePTMs has been implicated in a wide range of diseases, including cancer, metabolic disorders,neurological disorders, cardiovascular diseases, and bone diseases. Understanding the speciesof PTMs and functions regulated by various PTMs of LSD1 provides insights into its involvementin diverse physiological and pathological processes. In this review, we discuss the structuralcharacteristics of LSD1 and amino acid residues that affect its enzyme activity. We also summarize the potential PTMs that occur on LSD1 and their involvement in cellular processes.Furthermore, we describe human diseases associated with abnormal expression of LSD1. Thiscomprehensive analysis sheds light on the intricate interplay between PTMs and the functionsof LSD1, highlighting their significance in health and diseases. 展开更多
关键词 Enzyme activity Histone demethylase Human diseases LSD1 POST-TRANSLATIONAL
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